[Redbean] Feature / OnError(status, message) hook (#1103)

tool/net/definitions.lua

@@ -392,22 +392,22 @@ LUA ENHANCEMENTS
     - redbean supports a printf modulus operator, like Python. For
       example, you can say `"hello %s" % {"world"}` instead of
       `string.format("hello %s", "world")`.
-      
+
       --
       - redbean supports a string multiply operator, like Python. For
       example, you can say `"hi" * 2` instead of `string.rep("hi", 2)`.
-      
+
       - redbean supports octal (base 8) integer literals. For example
       `0644 == 420` is the case in redbean, whereas in upstream Lua
       `0644 == 644` would be the case.
-      
+
       - redbean supports binary (base 2) integer literals. For example
       `0b1010 == 10` is the case in redbean, whereas in upstream Lua
       `0b1010` would result in an error.
-      
+
       - redbean supports the GNU syntax for the ASCII ESC character in
       string literals. For example, `"\e"` is the same as `"\x1b"`.
-      
+
 ]]
 
 ---@class string
@@ -550,6 +550,17 @@ SPECIAL PATHS
 ---
 function OnHttpRequest() end
 
+--- Hooks catch errors
+---
+--- If this functiopn is defined in the global scope by your `/.init.lua`
+--- then any errors occuring in the OnHttpRequest() hook will be catched.
+--- You'll be able then to do whatever you need with the error status and
+--- error message.
+---
+---@param status uint16
+---@param message string
+function OnError(status, message) end
+
 --- Hooks client connection creation.
 ---
 --- If this function is defined it'll be called from the main process
@@ -1436,9 +1447,9 @@ function Log(level, message) end
 function ParseHttpDateTime(rfc1123) end
 
 --- Parses URL.
---- 
+---
 ---@return Url url An object containing the following fields is returned:
---- 
+---
 --- - `scheme` is a string, e.g. `"http"`
 --- - `user` is the username string, or nil if absent
 --- - `pass` is the password string, or nil if absent
@@ -1448,28 +1459,28 @@ function ParseHttpDateTime(rfc1123) end
 --- - `params` is the URL paramaters, e.g. `/?a=b&c` would be
 ---   represented as the data structure `{{"a", "b"}, {"c"}, ...}`
 --- - `fragment` is the stuff after the `#` character
---- 
+---
 ---@param url string
 ---@param flags integer? may have:
---- 
+---
 --- - `kUrlPlus` to turn `+` into space
 --- - `kUrlLatin1` to transcode ISO-8859-1 input into UTF-8
---- 
+---
 --- This parser is charset agnostic. Percent encoded bytes are
 --- decoded for all fields. Returned values might contain things
 --- like NUL characters, spaces, control codes, and non-canonical
 --- encodings. Absent can be discerned from empty by checking if
 --- the pointer is set.
---- 
+---
 --- There's no failure condition for this routine. This is a
 --- permissive parser. This doesn't normalize path segments like
---- `.` or `..` so use IsAcceptablePath() to check for those. No 
+--- `.` or `..` so use IsAcceptablePath() to check for those. No
 --- restrictions are imposed beyond that which is strictly
 --- necessary for parsing. All the data that is provided will be
 --- consumed to the one of the fields. Strict conformance is
 --- enforced on some fields more than others, like scheme, since
 --- it's the most non-deterministically defined field of them all.
---- 
+---
 --- Please note this is a URL parser, not a URI parser. Which
 --- means we support everything the URI spec says we should do
 --- except for the things we won't do, like tokenizing path
@@ -2244,7 +2255,7 @@ function ProgramTrustedIp(ip, cidr) end
 --- is granted per second to all buckets. The minimum value is 1/3600
 --- which means once per hour. The maximum value for this setting is
 --- 1e6, which means once every microsecond.
---- 
+---
 --- `cidr` is the specificity of judgement.  Since creating 2^32 buckets
 --- would need 4GB of RAM, redbean defaults this value to 24 which means
 --- filtering applies to class c network blocks (i.e. x.x.x.*), and your
@@ -2253,38 +2264,38 @@ function ProgramTrustedIp(ip, cidr) end
 --- number means you use less ram/cpu, but splash damage applies more to
 --- your clients; whereas higher numbers means more ram/cpu usage, while
 --- ensuring rate limiting only applies to specific compromised actors.
---- 
+---
 --- `reject` is the token count or treshold at which redbean should send
 --- 429 Too Many Request warnings to the client. Permitted values can be
 --- anywhere between -1 and 126 inclusively. The default value is 30 and
 --- -1 means disable to disable (assuming AcquireToken() will be used).
---- 
+---
 --- `ignore` is the token count or treshold, at which redbean should try
 --- simply ignoring clients and close the connection without logging any
 --- kind of warning, and without sending any response. The default value
 --- for this setting is `MIN(reject / 2, 15)`. This must be less than or
 --- equal to the `reject` setting. Allowed values are [-1,126] where you
 --- can use -1 as a means of disabling `ignore`.
---- 
+---
 --- `ban` is the token count at which redbean should report IP addresses
 --- to the blackhole daemon via a unix-domain socket datagram so they'll
 --- get banned in the kernel routing tables. redbean's default value for
 --- this setting is `MIN(ignore / 10, 1)`. Permitted values are [-1,126]
 --- where -1 may be used as a means of disabling the `ban` feature.
---- 
+---
 --- This function throws an exception if the constraints described above
 --- are not the case. Warnings are logged should redbean fail to connect
 --- to the blackhole daemon, assuming it hasn't been disabled. It's safe
 --- to use load balancing tools when banning is enabled, since you can't
 --- accidentally ban your own network interface addresses, loopback ips,
 --- or ProgramTrustedIp() addresses where these rate limits don't apply.
---- 
+---
 --- It's assumed will be called from the .init.lua global scope although
 --- it could be used in interpreter mode, or from a forked child process
 --- in which case the only processes that'll have ability to use it will
 --- be that same process, and any descendent processes. This function is
 --- only able to be called once.
---- 
+---
 --- This feature is not available in unsecure mode.
 ---@param replenish number?
 ---@param cidr integer?
@@ -2309,10 +2320,10 @@ function ProgramTokenBucket(replenish, cidr, reject, ignore, ban) end
 function AcquireToken(ip) end
 
 --- Counts number of tokens in bucket.
---- 
+---
 --- This function is the same as AcquireToken() except no subtraction is
 --- performed, i.e. no token is taken.
---- 
+---
 --- `ip` should be an IPv4 address and this defaults to GetClientAddr(),
 --- although other interpretations of its meaning are possible.
 ---@param ip uint32?
@@ -2326,12 +2337,12 @@ function CountTokens(ip) end
 --- based on the banned threshold. However if your Lua code calls
 --- `AcquireToken()` manually, then you'll need this function to take
 --- action on the returned values.
---- 
+---
 --- This function returns true if a datagram could be sent sucessfully.
 --- Otherwise false is returned, which can happen if blackholed isn't
 --- running, or if a lot of processes are sending messages to it and the
 --- operation would have blocked.
---- 
+---
 --- It's assumed that the blackholed service is running locally in the
 --- background.
 ---@param ip uint32
@@ -2416,7 +2427,7 @@ lsqlite3 = {
     --- An `lsqlite3.BUSY` error can occur at any point in a transaction: when
     --- the transaction is first started, during any write or update operations,
     --- or when the transaction commits. To avoid encountering `lsqlite3.BUSY`
-    --- errors in the middle of a transaction, the application can use 
+    --- errors in the middle of a transaction, the application can use
     --- `BEGIN IMMEDIATE` instead of just `BEGIN` to start a transaction. The
     --- `BEGIN IMMEDIATE` command might itself return `lsqlite3.BUSY`, but if it
     --- succeeds, then SQLite guarantees that no subsequent operations on the same database through the next COMMIT will return `lsqlite3.BUSY`.
@@ -2472,7 +2483,7 @@ lsqlite3 = {
     CORRUPT = 11,
     --- The `lsqlite3.NOTFOUND` result code is exposed in three ways:
     ---
-    --- `lsqlite3.NOTFOUND` can be returned by the `sqlite3_file_control()` 
+    --- `lsqlite3.NOTFOUND` can be returned by the `sqlite3_file_control()`
     --- interface to indicate that the file control opcode passed as the third
     --- argument was not recognized by the underlying VFS.
     ---
@@ -2491,7 +2502,7 @@ lsqlite3 = {
     --- complete because the disk is full. Note that this error can occur when
     --- trying to write information into the main database file, or it can also
     --- occur when writing into temporary disk files.
-    --- 
+    ---
     --- Sometimes applications encounter this error even though there is an
     --- abundance of primary disk space because the error occurs when writing
     --- into temporary disk files on a system where temporary files are stored
@@ -2521,19 +2532,19 @@ lsqlite3 = {
     --- the database schema was changed by some other process in between the
     --- time that the statement was prepared and the time the statement was run,
     --- this error can result.
-    --- 
+    ---
     --- The statement is automatically re-prepared if the schema changes, up to
     --- `SQLITE_MAX_SCHEMA_RETRY` times (default: 50). The `step()` interface
     --- will only return `lsqlite3.SCHEMA` back to the application if the
     --- failure persists after these many retries.
     SCHEMA = 17,
     --- The `lsqlite3.TOOBIG` error code indicates that a string or BLOB was too
-    --- large. The default maximum length of a string or BLOB in SQLite is 
+    --- large. The default maximum length of a string or BLOB in SQLite is
     --- 1,000,000,000 bytes. This maximum length can be changed at compile-time
     --- using the `SQLITE_MAX_LENGTH` compile-time option. The `lsqlite3.TOOBIG`
     --- error results when SQLite encounters a string or BLOB that exceeds the
     --- compile-time limit.
-    --- 
+    ---
     --- The `lsqlite3.TOOBIG` error code can also result when an oversized SQL
     --- statement is passed into one of the `db:prepare()` interface. The
     --- maximum length of an SQL statement defaults to a much smaller value of
@@ -2544,7 +2555,7 @@ lsqlite3 = {
     --- information about the failed constraint can be found by consulting the
     --- accompanying error message (returned via `errmsg()`) or by looking at
     --- the extended error code.
-    --- 
+    ---
     --- The `lsqlite3.CONSTRAINT` code can also be used as the return value from
     --- the `xBestIndex()` method of a virtual table implementation. When
     --- `xBestIndex()` returns `lsqlite3.CONSTRAINT`, that indicates that the
@@ -2558,7 +2569,7 @@ lsqlite3 = {
     --- BLOB in a column with a declared type of BOOLEAN. But in a few cases,
     --- SQLite is strict about types. The `lsqlite3.MISMATCH` error is returned
     --- in those few cases when the types do not match.
-    --- 
+    ---
     --- The rowid of a table must be an integer. Attempt to set the rowid to
     --- anything other than an integer (or a NULL which will be automatically
     --- converted into the next available integer rowid) results in an
@@ -2843,7 +2854,7 @@ function Database:close_vm(temponly) end
 ---@param func fun(udata: Udata) a Lua function that is invoked by SQLite3 whenever a transaction is committed. This callback receives one argument:
 ---@param udata Udata argument used when the callback was installed.
 ---
---- If `func` returns `false` or `nil` the COMMIT is allowed to proceed, 
+--- If `func` returns `false` or `nil` the COMMIT is allowed to proceed,
 --- otherwise the COMMIT is converted to a ROLLBACK.
 ---
 --- See: `db:rollback_hook` and `db:update_hook`
@@ -2898,7 +2909,7 @@ function Database:create_aggregate(name, nargs, step, final, userdata) end
 --- This creates a collation callback. A collation callback is used to establish
 --- a collation order, mostly for string comparisons and sorting purposes.
 ---@param name string the name of the collation to be created
----@param func fun(s1: string, s2: string): -1|0|1 a function that accepts two string arguments, compares them and returns `0` if both strings are identical, `-1` if the first argument is lower in the collation order than the second and `1` if the first argument is higher in the collation order than the second. 
+---@param func fun(s1: string, s2: string): -1|0|1 a function that accepts two string arguments, compares them and returns `0` if both strings are identical, `-1` if the first argument is lower in the collation order than the second and `1` if the first argument is higher in the collation order than the second.
 --- A simple example:
 ---
 ---    local function collate(s1,s2)
@@ -7263,15 +7274,15 @@ function unix.isatty(fd) end
 function unix.tiocgwinsz(fd) end
 
 --- Returns file descriptor of open anonymous file.
---- 
+---
 --- This creates a secure temporary file inside `$TMPDIR`. If it isn't
 --- defined, then `/tmp` is used on UNIX and GetTempPath() is used on
 --- the New Technology. This resolution of `$TMPDIR` happens once.
---- 
+---
 --- Once close() is called, the returned file is guaranteed to be
 --- deleted automatically. On UNIX the file is unlink()'d before this
 --- function returns. On the New Technology it happens upon close().
---- 
+---
 --- On the New Technology, temporary files created by this function
 --- should have better performance, because `kNtFileAttributeTemporary`
 --- asks the kernel to more aggressively cache and reduce i/o ops.
@@ -7284,7 +7295,7 @@ function unix.tmpfd() end
 function unix.sched_yield() end
 
 --- Creates interprocess shared memory mapping.
---- 
+---
 --- This function allocates special memory that'll be inherited across
 --- fork in a shared way. By default all memory in Redbean is "private"
 --- memory that's only viewable and editable to the process that owns
@@ -7294,15 +7305,15 @@ function unix.sched_yield() end
 --- don't want that to happen, and you want the memory to be shared
 --- similar to how it would be shared if you were using threads, then
 --- you can use this function to achieve just that.
---- 
+---
 --- The memory object this function returns may be accessed using its
 --- methods, which support atomics and futexes. It's very low-level.
 --- For example, you can use it to implement scalable mutexes:
---- 
+---
 ---     mem = unix.mapshared(8000 * 8)
---- 
+---
 ---     LOCK = 0 -- pick an arbitrary word index for lock
---- 
+---
 ---     -- From Futexes Are Tricky Version 1.1 § Mutex, Take 3;
 ---     -- Ulrich Drepper, Red Hat Incorporated, June 27, 2004.
 ---     function Lock()
@@ -7324,7 +7335,7 @@ function unix.sched_yield() end
 ---             mem:wake(LOCK, 1)
 ---         end
 ---     end
---- 
+---
 --- It's possible to accomplish the same thing as unix.mapshared()
 --- using files and unix.fcntl() advisory locks. However this goes
 --- significantly faster. For example, that's what SQLite does and
@@ -7333,7 +7344,7 @@ function unix.sched_yield() end
 --- might need something lower level than file locks, to implement
 --- things like throttling. Shared memory is a good way to do that
 --- since there's nothing that's faster.
---- 
+---
 ---@param size integer
 --- The `size` parameter needs to be a multiple of 8. The returned
 --- memory is zero initialized. When allocating shared memory, you
@@ -7341,7 +7352,7 @@ function unix.sched_yield() end
 --- overhead of allocating a single shared mapping is 500 words of
 --- resident memory and 8000 words of virtual memory. It's because
 --- the Cosmopolitan Libc mmap() granularity is 2**16.
---- 
+---
 --- This system call does not fail. An exception is instead thrown
 --- if sufficient memory isn't available.
 ---
@@ -7351,16 +7362,16 @@ function unix.mapshared(size) end
 ---@class unix.Memory: userdata
 --- unix.Memory encapsulates memory that's shared across fork() and
 --- this module provides the fundamental synchronization primitives
---- 
+---
 --- Redbean memory maps may be used in two ways:
---- 
+---
 --- 1. as an array of bytes a.k.a. a string
 --- 2. as an array of words a.k.a. integers
---- 
+---
 --- They're aliased, union, or overlapped views of the same memory.
 --- For example if you write a string to your memory region, you'll
 --- be able to read it back as an integer.
---- 
+---
 --- Reads, writes, and word operations will throw an exception if a
 --- memory boundary error or overflow occurs.
 unix.Memory = {}
@@ -7372,7 +7383,7 @@ unix.Memory = {}
 --- If `bytes` is none or nil, then the nul-terminated string at
 --- `offset` is returned. You may specify `bytes` to safely read
 --- binary data.
---- 
+---
 --- This operation happens atomically. Each shared mapping has a
 --- single lock which is used to synchronize reads and writes to
 --- that specific map. To make it scale, create additional maps.
@@ -7381,7 +7392,7 @@ unix.Memory = {}
 function unix.Memory:read(offset, bytes) end
 
 --- Writes bytes to memory region.
---- 
+---
 ---@param data string
 ---@param offset integer?
 --- `offset` is the starting byte index to which memory is copied,
@@ -7391,7 +7402,7 @@ function unix.Memory:read(offset, bytes) end
 --- If `bytes` is none or nil, then an implicit nil-terminator
 --- will be included after your `data` so things like json can
 --- be easily serialized to shared memory.
---- 
+---
 --- This operation happens atomically. Each shared mapping has a
 --- single lock which is used to synchronize reads and writes to
 --- that specific map. To make it scale, create additional maps.
@@ -7399,7 +7410,7 @@ function unix.Memory:write(data, offset, bytes) end
 
 
 --- Loads word from memory region.
---- 
+---
 --- This operation is atomic and has relaxed barrier semantics.
 ---@param word_index integer
 ---@return integer
@@ -7407,7 +7418,7 @@ function unix.Memory:write(data, offset, bytes) end
 function unix.Memory:load(word_index) end
 
 --- Stores word from memory region.
---- 
+---
 --- This operation is atomic and has relaxed barrier semantics.
 ---@param word_index integer
 ---@param value integer
@@ -7415,10 +7426,10 @@ function unix.Memory:store(word_index, value) end
 
 
 --- Exchanges value.
---- 
+---
 --- This sets word at `word_index` to `value` and returns the value
 --- previously held in by the word.
---- 
+---
 --- This operation is atomic and provides the same memory barrier
 --- semantics as the aligned x86 LOCK XCHG instruction.
 ---@param word_index integer
@@ -7427,12 +7438,12 @@ function unix.Memory:store(word_index, value) end
 function unix.Memory:xchg(word_index, value) end
 
 --- Compares and exchanges value.
---- 
+---
 --- This inspects the word at `word_index` and if its value is the same
 --- as `old` then it'll be replaced by the value `new`, in which case
 --- `true, old` shall be returned. If a different value was held at
 --- word, then `false` shall be returned along with the word.
---- 
+---
 --- This operation happens atomically and provides the same memory
 --- barrier semantics as the aligned x86 LOCK CMPXCHG instruction.
 ---@param word_index integer
@@ -7442,11 +7453,11 @@ function unix.Memory:xchg(word_index, value) end
 function unix.Memory:cmpxchg(word_index, old, new) end
 
 --- Fetches then adds value.
---- 
+---
 --- This method modifies the word at `word_index` to contain the sum of
 --- value and the `value` paremeter. This method then returns the value
 --- as it existed before the addition was performed.
---- 
+---
 --- This operation is atomic and provides the same memory barrier
 --- semantics as the aligned x86 LOCK XADD instruction.
 ---@param word_index integer
@@ -7455,7 +7466,7 @@ function unix.Memory:cmpxchg(word_index, old, new) end
 function unix.Memory:fetch_add(word_index, value) end
 
 --- Fetches and bitwise ands value.
---- 
+---
 --- This operation happens atomically and provides the same memory
 --- barrier ordering semantics as its x86 implementation.
 ---@param word_index integer
@@ -7464,7 +7475,7 @@ function unix.Memory:fetch_add(word_index, value) end
 function unix.Memory:fetch_and(word_index, value) end
 
 --- Fetches and bitwise ors value.
---- 
+---
 --- This operation happens atomically and provides the same memory
 --- barrier ordering semantics as its x86 implementation.
 ---@param word_index integer
@@ -7473,7 +7484,7 @@ function unix.Memory:fetch_and(word_index, value) end
 function unix.Memory:fetch_or(word_index, value) end
 
 --- Fetches and bitwise xors value.
---- 
+---
 --- This operation happens atomically and provides the same memory
 --- barrier ordering semantics as its x86 implementation.
 ---@param word_index integer
@@ -7482,24 +7493,24 @@ function unix.Memory:fetch_or(word_index, value) end
 function unix.Memory:fetch_xor(word_index, value) end
 
 --- Waits for word to have a different value.
---- 
+---
 --- This method asks the kernel to suspend the process until either the
 --- absolute deadline expires or we're woken up by another process that
 --- calls `unix.Memory:wake()`.
---- 
+---
 --- The `expect` parameter is used only upon entry to synchronize the
 --- transition to kernelspace. The kernel doesn't actually poll the
 --- memory location. It uses `expect` to make sure the process doesn't
 --- get added to the wait list unless it's sure that it needs to wait,
 --- since the kernel can only control the ordering of wait / wake calls
 --- across processes.
---- 
+---
 --- The default behavior is to wait until the heat death of the universe
 --- if necessary. You may alternatively specify an absolute deadline. If
 --- it's less than or equal to the value returned by clock_gettime, then
 --- this routine is non-blocking. Otherwise we'll block at most until
 --- the current time reaches the absolute deadline.
---- 
+---
 --- Futexes are currently supported on Linux, FreeBSD, OpenBSD. On other
 --- platforms this method calls sched_yield() and will either (1) return
 --- unix.EINTR if a deadline is specified, otherwise (2) 0 is returned.
@@ -7512,7 +7523,7 @@ function unix.Memory:fetch_xor(word_index, value) end
 --- well-supported on all supported platforms but requires using files.
 --- Please test your use case though, because it's kind of an edge case
 --- to have the scenario above, and chances are this op will work fine.
---- 
+---
 ---@return 0
 ---@overload fun(self, word_index: integer, expect: integer, abs_deadline?: integer, nanos?: integer): nil, error: unix.Errno
 ---
@@ -7520,10 +7531,10 @@ function unix.Memory:fetch_xor(word_index, value) end
 --- should use futexes inside a loop that is able to cope with spurious
 --- wakeups. We don't actually guarantee the value at word has in fact
 --- changed when this returns.
---- 
+---
 --- `EAGAIN` is raised if, upon entry, the word at `word_index` had a
 --- different value than what's specified at `expect`.
---- 
+---
 --- `ETIMEDOUT` is raised when the absolute deadline expires.
 ---
 ---@param word_index integer
@@ -7533,11 +7544,11 @@ function unix.Memory:fetch_xor(word_index, value) end
 function unix.Memory:wait(word_index, expect, abs_deadline, nanos) end
 
 --- Wakes other processes waiting on word.
---- 
+---
 --- This method may be used to signal or broadcast to waiters. The
 --- `count` specifies the number of processes that should be woken,
 --- which defaults to `INT_MAX`.
---- 
+---
 --- The return value is the number of processes that were actually woken
 --- as a result of the system call. No failure conditions are defined.
 ---@param index integer

tool/net/help.txt

@@ -576,6 +576,12 @@ HOOKS
           *). See functions like Route which asks redbean to do its default
           thing from the handler.
 
+  OnError(status:int, message:string)
+          If this function is defined and if any errors occurs in
+          OnHttpRequest() then this method will be called instead of displaying
+          the default error page. Useful if you need to display the error page
+          using your specific code or send it to any tier service.
+
   OnClientConnection(ip:int, port:int, serverip:int, serverport:int) → bool
           If this function is defined it'll be called from the main process
           each time redbean accepts a new client connection. If it returns

tool/net/redbean.c

@@ -456,6 +456,7 @@ static bool isexitingworker;
 static bool hasonworkerstart;
 static bool leakcrashreports;
 static bool hasonhttprequest;
+static bool hasonerror;
 static bool ishandlingrequest;
 static bool listeningonport443;
 static bool hasonprocesscreate;
@@ -2532,7 +2533,7 @@ img { vertical-align: middle; }\r\n\
   return p;
 }
 
-static char *ServeErrorImpl(unsigned code, const char *reason,
+static char *ServeErrorImplDefault(unsigned code, const char *reason,
                             const char *details) {
   size_t n;
   char *p, *s;
@@ -2570,6 +2571,28 @@ static char *ServeErrorImpl(unsigned code, const char *reason,
   }
 }
 
+static char *GetLuaResponse(void) {
+  return cpm.luaheaderp ? cpm.luaheaderp : SetStatus(200, "OK");
+}
+
+static char *ServeErrorImpl(unsigned code, const char *reason,
+                            const char *details) {
+  lua_State *L = GL;
+  if (hasonerror) {
+    lua_getglobal(L, "OnError");
+    lua_pushinteger(L, code);
+    lua_pushstring(L, reason);
+    if (LuaCallWithTrace(L, 2, 0, NULL) == LUA_OK) {
+      return CommitOutput(GetLuaResponse());
+    } else {
+      return ServeErrorImplDefault(code, reason, details);
+    }
+  } else {
+    return ServeErrorImplDefault(code, reason, details);
+  }
+
+}
+
 static char *ServeErrorWithPath(unsigned code, const char *reason,
                                 const char *path, size_t pathlen) {
   ERRORF("(srvr) server error: %d %s %`'.*s", code, reason, pathlen, path);
@@ -3227,10 +3250,6 @@ static char *ServeIndex(const char *path, size_t pathlen) {
   return p;
 }
 
-static char *GetLuaResponse(void) {
-  return cpm.luaheaderp ? cpm.luaheaderp : SetStatus(200, "OK");
-}
-
 static bool ShouldServeCrashReportDetails(void) {
   uint32_t ip;
   uint16_t port;
@@ -5569,6 +5588,7 @@ static void LuaInit(void) {
   }
   if (LuaRunAsset("/.init.lua", true)) {
     hasonhttprequest = IsHookDefined("OnHttpRequest");
+    hasonerror = IsHookDefined("OnError");
     hasonclientconnection = IsHookDefined("OnClientConnection");
     hasonprocesscreate = IsHookDefined("OnProcessCreate");
     hasonprocessdestroy = IsHookDefined("OnProcessDestroy");